Although genetic screening studies have provided some insight into the pathogenesis that underlies MM, the full landscape of genomic events driving cancer initiation, progression, and response to treatment have remained hidden from view. Drs. Ron A. DePinho from the Dana-Farber Cancer Institute, Cameron Brennan of Memorial Sloan-Kettering Cancer Center, and John Shaughnessy of the Myeloma Institute for Research and Therapy at the University of Arkansas for Medical Sciences and their colleagues performed a high-resolution and integrated analysis of gene copy number alterations and expression profiles of outcome-annotated MM clinical specimens.
The researchers discovered a high level of molecular heterogeneity typified by many new recurrent amplifications and deletions that point to a large number of yet-to-be-discovered oncogenes and tumor suppressor genes. These amplification and deletion patterns define new disease subgroups of MM that are characterized by varied dysregulation of distinct cancer-relevant genes and can be correlated with different clinical outcomes. Importantly, several candidate genes identified in this study possess broad clinical and biological relevance, as they are also associated with histologically unrelated malignancies such as pancreatic, lung, breast, and ovarian cancer and may thus represent a rite of passage for many different cancers.
"This integrated and detailed view of the MM genome is consisten t with the concept of widespread changes in the expression of genes with cancer activity in the pathogenesis of MM, a concept with therapeutic and diagnostic implication for MM in particular and cancer in general," explains Dr. DePinho. The researchers suggest that on a broader scale in relation to the human cancer genome project, their results will serve to direct costly sequencing efforts toward those specific regions that contain genes displaying high pathogenic relevance. "This story clearly indicates that we are dealing with the tip of the iceberg when it comes to the universe of cancer genes," says Dr. DePinho.